Resending to mailng list due to HTML formatting . . . sorry.
-- Alison
---
On Fri, Jul 8, 2022 at 10:19 AM Joel Fernandes <joel@xxxxxxxxxxxxxxxxx> wrote:
>
> Dear Paul and Frederic,
>
> Len Brown on CC provided a good idea in a meeting on using intel_pstate to
> detect if device is a server or a consumer device.
Robots are neither a server nor a consumer device. Please let's not
force industrial users of RT to choose between two inapt sets of
configuration options.
>
> Can we perhaps use this to trigger the offload/nocb mechanisms on consumer
> devices / distros? I was thinking the dynamic offload and the "one kernel"
> work that Frederic did can be trigger from such detection.
>
> It is true userspace can do the trigger, but maybe it is better to not leave
> it to userspace so we'd save power on bad userspaces.
>
> Come to think of it, this can even be done at boot time if we can read the
> below state early enough:
>
> > intel_pstate.c demonstrates how to detect a server when ACPI is present:
> >
> >
> >
> > #ifdef CONFIG_ACPI
> >
> >
> >
> > static bool intel_pstate_acpi_pm_profile_server(void)
> >
> > {
> >
> > if (acpi_gbl_FADT.preferred_profile =3D=3D PM_ENTERPRISE_SERVER |=
> |
> >
> > acpi_gbl_FADT.preferred_profile =3D=3D PM_PERFORMANCE_SERVER)
> >
> > return true;
> >
> >
> >
> > return false;
> >
> > }
> >
Robotics applications often rely on fairly "big iron" that is
configured with CONFIG_CPU_FREQ_GOV_PERFORMANCE=y. Servers and
robotics are quite different use cases, so setting configuration that
would be useful for servers whenever the CPU_FREQ_GOV_PERFORMANCE is
selected would create a headache for many users.
I know, how about a new CONFIG_ANDROID?*
Best wishes,
Alison Chaiken
Aurora Innovation
*That was a joke.
